Crankcase air-pressure control means



May 8, 1945 w. G. WINKELS ETAL .2,375,718

CRANKCASE IR-PRESSURE. CONTROLMEANS v Filed April 23, 194s .72' 58 75ATTORNEY Patented May 8, 1945 MEAN `Walter G;- vvirikn, United statesNavy, and Thomas W. Ashcroft`Be`loit`, Wis., assignors to Fairbanks;Morse &"Oo., Chicago, "Illu,

a cor- Appncation April 23, 1943, serial No. 484,194

(c1. 1er- 194) 9^ Gl'aims; This'invention relates. to crankcaseair-pressure control means, andn moreV particularly toian improveddevice for controlling air-pressure within a substantially closed`cranls'casev of an internal combustion eng-ine,l pump, compressor orthe like.

A `principal object of thepresent invention resides in the provisionv ofa novel and effectivecontrol device for substantiallyI closedVcrankcases of engines and the like, which affords crankcase compressionrelief `and air-pressure` controlin aimanner generally'to prevent`above-atmospheric; air

pressures within thecrankcase during engine `operation, andmoreparticularly, tofacilitate maintenance of sub-atmospheric pressuresin the l crankcase, evento the extent of a slight negative pressure orpartial vacuum therein, throughout at least a greater portion `of eachcycle ofengine piston` operation, whereby there is thus prevented or`very materiallyureduced such loss oflubricat- -ing `uid from thecrankcase interior, as otherwise would tend to occur by reason ofabove-atmospheric air pressure in thecrankcase tending to forcelubricant outwardly, as throughV `cylinder ports, crankcase joints,andgpast such `operating parts of the engine which extend through wallportions of the crankcase.

` i Another object of theinvention resides in the provisions` of arelatively compact andI effective crankcase air control device of thecharacter `inydicated', adapted for controlling the `pressure `Within;`the, crankcase by release from the crankcase during engineoperaffording periodic air ation, wherein` therdeviceembodies alubricant 'condensing chamberfand` lubricant absorbing meansthereinf'orthe removal ofV lubricant from the crankcase air releasedthrough the device, and controlled means for effecting; return of thelubricant thus removed, to the crankcasa A further `object oftheinventionis to provide an improved device for `the purpose indicated,p

which utilizes an operating partofr the engine as an active element ofthe. device; and which pro- Vides an` oil entrappingl and.condensingshield `ai'. theoutlet thereof-l for insuring againstdischarge ofA oil particles inte the-r` atmosphere about the engine.` i

f l `Other objectsand advantages of theinvention I will appear from4 thefollowing' description of a preferred embodiment thereofl as exemplified`in the accompanying drawing, in which:

Fig. 1 is a longitudinali elevation partly section of an internalcombustion engine embodying the presently improved crankcase air`controlldevice;

generally at I0.

upper portionor the crankcase, taken from the line 2--2 in` Fig. ,1,showing the crankcaseV device.

therein, the View alsoillustrating a magneto'device in driven connectionwith a drive gear in the crankcaseportion shown, and Fig. 3` isa-sectional elevation through 'theeleviceas viewed from 1ine3-3 inFig.2. l

Referring to the drawing by suitable characters of reference, theimproved control device in the embodiment presently preferred and`herein illustrated, is-shown by Way of an` example `of its application,in association with an internal combustion engine of closed `crankcasetype, indicated Briefly, the enginel shown by Fig. 1 includes a frameassembly providing a cylinder II anda crankcaseIZ, acrankshaft I4 in thecrankcase, a piston I5 operable-.in cylinder II, and a'connecting rod I6between the pistonand crankshaft., All magneto generator I8 (Fig.2)provided for supplying engine ignition current, is arranged externallyto and preferably above the crankcase I-2 adjacent anupward extensionrI9 of the crankcase An opening: 20 in one Wall 22A of crankcaseextension I9 `aiiords projection of` the magneto shaft couplingelement123 int the chamber 2lil provided-by the extension I9, for drivenconnection `with a gear j i 26 therein forming an element of! a geartrain Fig. 2 is an enlarged sectional-elevation or an 55 in the outerVertical wall comprising enmeshing gears 26, 2l,` 28 and 30. Thel lattergear `3l) is located on and driven by the crankshaft I4, so that themagneto is operated from thel crankshaftl through `the described geartrain. For a purpose hereinafter to appear,

` the gear-driveratio of the gear train is such that -1 the gear 26 and.hence the-magneto shaft,` will be rotated atiengine crankshaft speed,although not necessarily in the same direction as crankshaft rotation. p

Since the chamber ,2.4i of extension I9 is in full communication withther main crankcasef chamber 3|, as appears `in Fig.` 2, the openingrreceiving the magneto shaft coupling 23 therethrough, ist sealed aboutthe mag-neto frameextension 32 at/the `opening in, any suitable manner,

- `as by a gasket indicatedI at-34.

The device of the present invention. isf located inI the crankcaseextension i 9, as appears inFigs. Zta-nd 34,- and` employs the magnetodrive gear `2li asian element thereon An aperture 35 is provided 36` ofcrankcase extension` I.9.,.. giving access to the extension chamber24and'this opening is normally closed by a removable: closure plate orcover member 38 which is suitably sealed at the opening, by a gasket 39or like means. Centrally of the closure plate and projectinghorizontally and inwardly therefrom, is a gear support or spindle 40which by preference, is formed integrally with the closure. The spindleis reduced as at 42 to provide a shoulder 43 and a gear journalling seat44 over the inner longitudinal end portion of the spindle. Gear 26rotatably receivedon spindle seat 44 and against shoulder 43, is formedto provide a cylindrical hub extension 46 having an end wall 41transversely notched or recessed as at 48, for driving connection to themagneto shaft coupling 23 by means of coupling lugs 56 engaged in thegear hub recesses 48 (Fig. 2).

The spindle 4|) is interiorly recessed longitudii nally thereof, toprovide a chamber 5| open at its outer end 52 and closed at its oppositeor inner end 54 by a spindle end walll55, the chamber as shown by Figs.2 and 3, preferably being of cylindrical form and tapered convergentlytoward the open end 52 thereof. Communication between 'the spindlechamber 5| and the chamber 24 in the crankcase extension i9, is eiectedthrough an upper inlet port 56 through the spindle wall at the inner end54 of the chamber 5|, and a diametrically opposite outlet port 58 oflesser capacity. The hub extension 46 of gear 26which overlies thespindle portion in which the ports 56 and 58 are located, is hereutilized as a rotary v alve element for controlling port communicationwith the chamber 24 of the crankcase extension I9. To this end, the gearhub is provided with an aperture 59 preferably of a diameter equivalentto the diameter of the larger port 56 in the spindle, located forsuccessive registry with theA ports 56 and 58 during rotation of thegear 26.

A discharge or outlet attachment generally indicated at 68, is suitablyremovably secured on the external face of the closure member 38 inregistry with the open end 52 of the spindle chamber 5|, and includes acasing 62 and an upwardly directed discharge neck 63 open at its upperend 64. A protective cap or hood 66 overlying the open end of dischargeneck 63 and projecting laterally on opposite sides thereof, as

'at 61 (Fig. 3), provides for downward air discharge through theopenings 68. As indicated, the attachment casing 62 is sealed in itsassembly connection to the closure 38 as by a suitable gasket element10.

Opposed longitudinal channels 1| in the walls of the spindle chamber 5|,afford a support for a removable screen 12 preferably of coarse wiremesh which extends horizontally through the chamber 5| and the chamber14 provided by the attachment casing 62. Bearing on the upper surface ofthe screen 12 within the chamber 5|, is an oil-absorbent member of feltpad which may have its longitudinal margins 16 compressed in thechannels 1| as shown. The pad further may be attached directly to thescreen by a suitable clasp or staple element 18, so that the screen andpad may b'e inserted or removed as a unit.

In the operation of the presently improved crankcase air control device,the gear 26 is set initially such that its hub valve aperture 59 is infull registry With the upper spindle port 56, when the engine piston isnear the crank end of its stroke. Thereafter and during engineoperation, the gear 26 rotated from the crankshaft at engine speed, willestablish successively, a rela tively short-period opening of thecrankcase chamber to the atmosphere through the chamber 24 of crankcaseextension |9, gear valve aperture 59 in register with spindle` port 56,spindle chamber 5|, chamber 14 of attachment or shield toward the crankend of itsstroke, the control device then becomes effective to vent tcatmosphere some of the crankcase air, whereby to relieve the slight,above-atmospheric air pressure in the crankcase so as immediately torestore the crankcase air pressure to atmospheric or sub.

atmosphericv value. Since in the normal function of the engine, some oilwill be entrapped in the air thus released, this oil must be removed inthe compression-relieving process. To this end, the spindle chamber 5|through which the oil-laden crankcase air passes, serves in thepresently preferred embodimentof the device, as an oil condensingchamber for removing some of the oil from the-air vented therethrough.The oil thus condensed in the chamber, collects on and is absorbed bythe felt pad 15 on screen i12, and hence is prevented from passing tothe exterior of the device. The felt pad 15 being centrally disposed inchamber 5| and hence directly in the pathof air flow therethrough, isof. itself an effectiveagency for direct absorption of oil particlesentrapped in the air vented through the chamber. Thus by the condensingfunction of the chamber 5| and the oil absorbing actionof the Ypad 15therein, a major portion of the oil in the Vented crankcase air, will beremoved for ultimate return to the crankcase. vSuch small portion of oilas may remain in the air attaining the chamber 14 and'neck 63 of theattachment 6, will be condensed therein and will collect in the zones ofchambers 14 and 5| below the screen 12.v Similarly, oil accumulated bythe absorbent pad 15 ultimately will drip through the screen into thelower portion of chamber 5|. It is to be noted that the wire mesh screen12 has an important function-in the present assembly, in that iteffectively prevents the air vented to atmosphere through the chambers5| and 14, from picking up any of the oil accumulating below the the cilaccumulated in the chamber below the screen 12 and collecting in theZone of the port 58 by reason of the tapered form of -chamber 5|, willbe returned by suction through port 58 and gear aperture 59 into thechamber 24 of crankcase extension I9, and thence into the enginecrankcase. In the normal and intended function of the device,atmospheric air will not be drawn into the crankcase `in this stageofoperation, this by reason of the limited capacity of the port 58 andthe relatively short period in which it is opened to the crankcase byvalve portV 59, which thus enables the lubricant pool in chamber 5| andabove the port 58, to act as an air seal even during the suction returnof a portion thereof toy the crankcase. f l

`extend through wall The resulting suctionuetention of-l lubricating`iiuidfin the crankcase, together with the return j ltherein may phere,means including a cravatte mom. theforegumg description df operation, it

willi appear now that` the;control` deviceai'n: its i function torelieve crankcase compression in the compression cycleof engine pistonoperation, and to prevent suction return ofair' to the crankcase inAthecycle of pistonlsuctidn eit'ect in* the crank-e case, affords a fullyeffective means for controlling crankcase air pressures to the extentthat itA prevents existence ci aboveatmospheric` prese sure therein, andfacilitates maintenance `of subatmospheric or even? a 4slight negativepressure i or slightfvacuuminthe crankcase, during at least the greaterportion of each gine piston operation. Asa consequence of thesub'atmospheric pressures or slight vacuum thus established inthe-cranltcase, the crankcase lubrieating iiuidf is most effectivelyretained therein,

against `leakage or loss to the crankcase4 exterior, as through cylinderports, crankcase joints, and past i such operating' partsfof the enginewhich portions of the crankcase.

thereto, of i'lui'd condensed and otherwise re1- moved `frornthecrankcase air vented toV atmos-` pher-e through the present novelcontrol device, eiectivelyi conserves the crankcase' lubricating fluidto an important degree, as will be now fully appreciated. H

The present crankcase air-pressure control de vice fully attains theobjects herein expressed and additionally, `presents a relativelycompact mechanism having but few parts,` and wherein the operating valveelementthereof is embodied by preference, in the engine driven magnetodrive gear of the engine assembly` illustrated.

- Although the device isshown herein as applied lined by the appendedclaims.`

We claim:

complete' c vcle of ene crankoase inl eachperiod of dei/clomid"suction`inthe crank;

M a; A'r control` dene-dorme character described for a substantiallyclosed-Y crankcase, comprising a-memberextending within the enginecran'kcase andprovided'with a chamber therein open to thea-tmosphere;`said member having spaced ports `communicatingl withsaidfchamlberj. `valve means in" control of said" ports and operable forsuccessively opening the ports to the `crankcase `interior,`anclva-lveactuating means for operating' said valve meansv in timedrelation to the cycleof developed pressure and suctionvin thecrankcashe, the operation `of said valve means thereby serv` ing teopenl oney of said ports in the periodsor` .piston developed pressureand the other portan the periods" of pistondeveloped suction in the 41Awcrankcase air-pressure control device for internal Acombustionengines-,` comprising ameni-` lber extending within thev enginecrankcase and i provided with a chamber therein open to the-atmosphere,said member havingspaced ports communicating Withjsaid`-ch`amber, anelement rotata-ble on said mem-ber in a position: toj overlie saidportsY and; having' an"openingjtherei1r lo'- cated-for registry with'said ports, said element l `during rotation serving throughsaid openingtherein, to open said ports to the crankcase interior, and enginecontrolled means for operating said element in timed relation to thecyother port in the l. .A control device of the character `describedforA a substantially closed erankcase, comprising means providing a`chamber openlto the atmosvalve. for establishing cle of developed'pressure and suction in the crankcase. and means controlled by thevalve,

for establishing in the suction period of said cycle, communication thecrankcase. Y.

2. A control device of the character described between said chamber andfor asubstantially` closed crankcase, comprising a member havingachamber therein open to the atmosphere and provided with spacedports forcommunication with the crankcase interior, and;

valve means operatively supported bysaid member, adapted for openingsaid 7ports to theV crank# case interior in each cycle of` developedpressure and suction in the crankcase,` such that one of pistondeveloped permit discharge lairthroughsaid chamber; and for opening thet of lubricant collected in said @lumber `by said f collector means in`cle of piston developed pressure and suction in the crankcase, theoperation of saidfelement thereby, serving to open one of said ports inthe periods of piston developed pressure and the i periods of pistondeveloped suc tion inthe crankcase. l 5. A crankcase air-pressurecontro-1 device for internal` combustion engines, comprising a memberproviding a lubricant condensing chamber for lubricant-laden air, saidchamber fbeing open to atmosphere and having spaced `ports -for com-`munication with the crankcase interior, and engine controlledvalverneans `in control or' said ports, adaptedfor opening one of saidports in the period of piston developed pressure in the` ,crankcasa topermit passage of lubricant-laden crankcase Lair through said condensingchamber, and for opening the other of said ports `period of crankcasesuction, to effect suction return to the cra-nkcase of lubricantcondensed in,"

said chamber. i

'6. A` crankcase air-pressure control device for internal combustionengines, comprising a memlber projecting within the engine crankcase andhaving a chamber phere, said member` being provided with spaced portsaffording communication 'between the chamber and the said chamber, andanengine actuated rotary valve on said member, effective for opening oneof said ports in the period of pressure in the crankcase, to o-flubricant-laden crankcase other of said ports in the period of crankcasesuction, to eiect suction return to thecrankcase collector means.

' said ports isthereby opened in each period of developed pressure` andthe other port opened '7. A crankcase air-pressure control device forinternal combustion engines, comprising a member extending into theengine crankcase and providing a chamber' therein open to the crankcaseexterior, said chamber having spaced ports for communication with thecrankcas'e interior, a

in the therein "open to the atmoscrankcase interior, lubricant ohamberedoutlet attachment in registry with the open end of said chamber, anengine controlled valve on said member, adapted for open-f ing one ofsaid ports to the crankcase interior in the period of piston developedpressure in the crankcase, for `permitting discharge of lubricantladencrankcase air through said chamber and said chambered outlet attachment,and means including the ohambered outlet attachment, effective forcondensing and collecting lubricant from the crankcase air dischargedthrough said chamber and attachment, said valve being effective intheperiod of crankcase suction, to open the other of said ports for thesuction return to the crankcase of lubricant collected by said means. vY

v8. The combination with an internal combustion engine providing anengine driven gear in the crankcase for operating a device adjunctive tothe engine organization, of a crankcase airpressure control devicecomprising a member eX- tending within the crankcase and providing abearing support l-for said gear, said memberhaving a chamber thereinopen to the atmosphere and spaced ports for communication with the rcrankcase interior, said gear -being adapted as a control valve for saidports, operable for opening 1 one 'of saidports to the crankcaseinterior in each periodV of pistony developed pressure in the crankcase,and for opening another of the ports thereto in each period of pistondeveloped suction in the crankcase.

9. The combination with an internal combustion engine providing anengine driven gear in the crankcase having a hub extension for driving`connection with a device adjunctive to the engine organization, of acrankcase air-pressure control device comprising a member extendingWithin the crankcase and providing a bearing support for said gear andhub extension, said member providing a chamber thereinopento theatmosphere

